Hi Geert, Thank you for the patch. On Monday 15 February 2016 22:16:50 Geert Uytterhoeven wrote: > The Renesas R-Car System Controller provides power management for the > CPU cores and various coprocessors, following the generic PM domain > bindings in Documentation/devicetree/bindings/power/power_domain.txt. > > This supports R-Car Gen1, Gen2, and Gen3. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > --- > Alternatives I considered: > > - Using a single node per power register block, even if it contains > multiple domains, e.g.: > > pd_ca15_scu: ca15_scu@180 { > reg = <0x180 0x20>; > #address-cells = <1>; > #size-cells = <0>; > #power-domain-cells = <0>; > renesas,interrupt-bits = <12>; > > pd_ca15_cpu: ca15_cpu@40 { > reg = <0x40 0x20>; > #power-domain-cells = <1>; > renesas,pm-domain-indices = <0 1>; > renesas,pm-domain-names = > "ca15_cpu0", "ca15_cpu1"; > renesas,interrupt-bits = <0 1>; > }; > }; > > Notes: > - You cannot just have a property with the number of domains, as > index 0 is not used on R-Car H1. Hence the need for > "renesas,pm-domain-indices" and "renesas,interrupt-bits", > - "#power-domain-cells = <1>" for nodes with multiple domains, > which allows typos in "power-domains = <&pd_ca15_cpu n>", using > an invalid value of "n". > > - Using a linear description in DT: > - Needs parent links for subdomains, > - More complicated to parse (lesson learned from R-Mobile PM > Domain support). > > - Keeping the power register block offset and the bit number as separate > "reg" cells, increasing "#address-cells" from 2 to 3, > > - Merging the interrupt bit (which needs only 5 bits) in the other "reg" > cell, decreasing "#address-cells" from 2 to 1. > > v2: > - Add R-Car H3 (r8a7795) support, > - Use "renesas,<type>-sysc" instead of "renesas,sysc-<type>", > - Add fallback compatibility strings for R-Car Gen2 and Gen3. > --- > .../bindings/power/renesas,sysc-rcar.txt | 87 +++++++++++++++++++ > 1 file changed, 87 insertions(+) create mode 100644 > Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt > > diff --git a/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt > b/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt new file > mode 100644 > index 0000000000000000..92ddc0da7b755215 > --- /dev/null > +++ b/Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt > @@ -0,0 +1,87 @@ > +DT bindings for the Renesas R-Car System Controller > + > +== System Controller Node == > + > +The R-Car System Controller provides power management for the CPU cores and > +various coprocessors. > + > +Required properties: > + - compatible: Must contain one or more of the following: > + - "renesas,r8a7779-sysc" (R-Car H1) > + - "renesas,r8a7790-sysc" (R-Car H2) > + - "renesas,r8a7791-sysc" (R-Car M2-W) > + - "renesas,r8a7792-sysc" (R-Car V2H) > + - "renesas,r8a7793-sysc" (R-Car M2-N) > + - "renesas,r8a7794-sysc" (R-Car E2) > + - "renesas,r8a7795-sysc" (R-Car H3) > + - "renesas,rcar-gen2-sysc" (Generic R-Car Gen2) > + - "renesas,rcar-gen3-sysc" (Generic R-Car Gen3) > + When compatible with the generic version, nodes must list the > SoC-specific > + version corresponding to the platform first, followed by the generic > + version. > + - reg: Address start and address range for the device. This isn't correct. I'll refrain from saying we abuse the reg property, as using the first cell as a power domain number should be fine (the second cell feels a bit more of an abuse to me though, but I won't complain too much), but the bindings document should describe what the reg cells contain. > + - pm-domains: This node contains a hierarchy of PM Domain Nodes. Can't it be an issue that the node happens to have the same name as the standard pm-domains property ? > + Dependencies (e.g. parent SCUs should not be powered off while child > CPUs > + are on) should be reflected using subnodes. > + > + > +== PM Domain Nodes == > + > +Each of the PM domain nodes represents a PM domain, as documented by the > +generic PM domain bindings in > +Documentation/devicetree/bindings/power/power_domain.txt. > + > +Required properties: > + - #power-domain-cells: Must be 0. > + - reg: This property must contain 2 values: > + - The first value is the number of the interrupt bit representing > + the power area in the various Interrupt Registers (e.g. SYSCISR, > + Interrupt Status Register), > + - The second value encodes the power register block offset (which is > + a multiple of 64), and the number of the bit representing the > + power area in the various Power Control Registers (e.g. PWROFFSR, > + Power Shutoff Status Register). This value is created by ORing > + these two numbers. > + The parent's node must contain the following two properties: > + - #address-cells: Must be 2, > + - #size-cells: Must be 0. > + > + > +Example: > + > + sysc: system-controller@e6180000 { > + compatible = "renesas,r8a7791-sysc", "renesas,rcar-gen2-sysc"; > + reg = <0 0xe6180000 0 0x0200>; > + > + pm-domains { > + #address-cells = <2>; > + #size-cells = <0>; > + > + pd_ca15_scu: scu@12 { > + reg = <12 0x180>; > + #address-cells = <2>; > + #size-cells = <0>; > + #power-domain-cells = <0>; > + > + pd_ca15_cpu0: cpu@0 { > + reg = <0 0x40>; > + #power-domain-cells = <0>; > + }; > + > + pd_ca15_cpu1: cpu@1 { > + reg = <1 0x41>; > + #power-domain-cells = <0>; > + }; > + }; > + > + pd_sh: sh@16 { > + reg = <16 0x80>; > + #power-domain-cells = <0>; > + }; > + > + pd_sgx: sgx@20 { > + reg = <20 0xc0>; > + #power-domain-cells = <0>; > + }; > + }; > + }; -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html